: Installing a shower enclosure in 2nd floor bath in 2 story home with basement. The plan is to run the drain under the ceiling which is above the stairway to the basement, over 2 feet, then straight down approx 9 feet, then turn left sloping beneath the 1st floor joists approx 10 feet to the main stack. It has been suggested that for the vent I should run it up into the attic and screw in a boca venting device. Good Idea? or should I run it up then over the 10 feet and tie into the main stack which happens to be the same one that the fixture would drain into? Help!